黄土高原不同草地类型对水稳性团聚体粒径分布及稳定性的影响

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黄泽, 田福平, 刘玉, 张静鸽, 苗海涛, 武高林. 黄土高原不同草地类型对水稳性团聚体粒径分布及稳定性的影响. 草业学报, 2017,26(11): 216-221
HUANG Ze, TIAN Fu-Ping, LIU Yu, ZHANG Jing-Ge, MIAO Hai-Tao, WU Gao-Lin. Effects of different grassland types on particle size distribution and stability of water stable aggregate on the Loess Plateau. Acta Prataculturae Sinica,2017,26(11): 216-221 复制到剪切板

Doi:10.11686/cyxb2017053
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黄土高原不同草地类型对水稳性团聚体粒径分布及稳定性的影响

黄泽^1,^2,³, 田福平², 刘玉¹, 张静鸽^1,², 苗海涛^1,², 武高林^1,^2,^*

1.西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌 712100

2.中国农业科学院兰州畜牧与兽药研究所,农业部兰州黄土高原生态环境重点野外科学观测试验站,甘肃兰州 730050

3.西北农林科技大学林学院,陕西杨凌 712100

*通信作者Corresponding author. E-mail: gaolinwu@gmail.com

作者简介:黄泽(1991-),女,宁夏银川人,在读硕士。E-mail: huangzee130@163.com

收稿日期: 2017-02-17

基金项目:国家自然科学基金项目(41525003, 31372368),中国科学院“西部之光”项目(XAB2015A04), 中国科学院青年创新促进会(2011288)和中国农业科学院创新工程专项资金项目(CAAS-ASTIP-2014-LIHPS-08)资助

摘要

本研究在甘肃兰州选择了4种不同类型的人工草地与天然草地为研究对象,分别为苜蓿草地、冰草草地、柠条灌木草地及针茅草地,其中针茅草地为天然草地。分析了4种草地类型0~40 cm土层的土壤水稳性团聚体粒径分布特征、平均重量直径(mean weight diameter, MWD)以及它们之间的差异性和相关性。结果表明,>2 mm和<0.25 mm粒径的水稳性团聚体为优势粒径;在土壤表层0~20 cm,针茅草地>0.25 mm粒径的水稳性团聚体显著高于其他草地类型( P<0.05),而在20~40 cm土层,苜蓿草地最高,说明在表层针茅草地对土壤结构的改良最优,随土层加深苜蓿草地对土壤结构的改良效果突出;苜蓿草地MWD值由表层0~10 cm的1.04 mm降低到30~40 cm的0.72 mm,下降了31%,而其他草地类型下降了50%~80%,说明苜蓿草地对不同层次土壤结构改良效果的差异性最小。MWD值与>0.25 mm粒径的水稳性团聚体含量和有机质呈极显著的正相关关系,与土壤容重呈极显著的负相关关系,表明水稳性大团聚体和有机质含量的增加可有效促进土壤结构的改良,加强土壤结构的稳定性,提高土壤的抗侵蚀能力。

关键词: 草地类型; 土壤结构; 平均重量直径; 有机质

Effects of different grassland types on particle size distribution and stability of water stable aggregate on the Loess Plateau

HUANG Ze^1,^2,³, TIAN Fu-Ping², LIU Yu¹, ZHANG Jing-Ge^1,², MIAO Hai-Tao^1,², WU Gao-Lin^1,^2,^*

1.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A & F University, Yangling 712100, China

2.Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Sciences, The Lanzhou Scientific Observation and Experiment Field Station of Ministry of Agriculture for Ecological System in the Loess Plateau, Lanzhou 730050, China

3.College of Forestry, Northwest A & F University, Yangling 712100, China

Abstract

Vegetation restoration can promote the formation of soil aggregates. The stability of soil structure is related to the water-stable aggregate content. The higher the content of water-stable aggregates, the more is the improvement in the soil erosion-resistance. Different plants have different effects on the water-stable aggregate component of soils. To evaluate the stability of soil structure under different grasslands, we studied different artificial grasslands and natural grasslands, including Medicago sativa, Agropyron cristatum, Caragana korshinskii and Stipa capillata in Lanzhou city, Gansu province. A soil aggregate analyzer was used to measure the size distribution of water-stable aggregates. The aggregate size differences and correlation of particle size distribution and mean weight diameter (MWD) of water-stable aggregate of the four different grasslands were analysed for the 0-40 cm soil depth. The results showed that the most abundant particle size of water-stable aggregates was >2 mm or <0.25 mm. For the 0-20 cm depth the proportion of water-stable aggregates of >0.25 mm particle size in S.capillata grassland was significantly higher than other grasslands ( P<0.05). For the 20-40 cm depth, the proportion of water-stable aggregates of >0.25 mm particle size was highest in M. sativa grassland. Hence, S.capillata grassland had the most improved soil structure for the 0-20 cm depth, while the M. sativa grassland had a better effect on soil structure at greater depth in the soil profiles. The MWD value for soil samples from M. sativa grassland decreased 31% from 1.04 mm in the 0-10 cm depth to 0.72 mm in 30-40 cm soil depth. These results indicate that in M. sativa grassland, soil structure improvement does not greatly differ between soil depths. There were extremely significant correlations between the MWD value, the proportion of water-stable aggregate in >0.25 mm particle size category and soil organic matter content. Generally, the MWD value and soil bulk density were significantly and negatively correlated. The results demonstrate that increase in the proportion of soil water-stable macro-aggregate and soil organic matter are effective ways to promote soil structure improvement, and enhance soil structure stability and resistance to erosion.

Keyword: grassland types; soil structure; mean weight diameter; soil organic matter

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黄土高原生态环境脆弱, 植被退化严重, 土壤侵蚀剧烈, 1950年实施退耕还林还草工程以来, 区域生态环境得以恢复, 土壤侵蚀得到控制^[1]。土壤侵蚀与土壤结构的改变有着密切联系, 土壤团聚体是土壤结构的基本单位, 其组成和稳定性是土壤结构变化的重要指示因子, 对水土流失和入渗能力有重要影响^{[2, 3]}。各粒径水稳性团聚体的比例可以反映土壤团聚体的质量^[4], 因此土壤水稳性团聚体的数量和特征可以反映土壤结构的稳定性和抗侵蚀能力^{[5, 6]}。> 0.25 mm粒径的水稳性团聚体可以作为评价土壤结构的指标, 其含量越高, 说明土壤结构越稳定, 土壤抗侵蚀能力越强^{[7, 8]}。植被恢复有利于促进土壤大团聚体的形成^[5]。不同的植物群落对团聚体稳定性影响不同^[9]。黄土高原受水分条件限制, 植被恢复方式多以种草为主, 草本植物根系能固持土壤, 改良土壤结构, 促进水稳性团粒的形成, 降低土壤侵蚀^[10]。

土壤团聚体的大小和稳定性, 是反应土壤物理性质的重要指标, 因此可作为监测和评估草地恢复或退化的指示因子, 很少有人研究自然植被恢复和人工植被恢复土壤团聚体粒径分布和稳定性的差异, 因此本研究选择了4种不同植被类型的人工草地与天然草地, 研究其水稳性团聚体粒径分布以及平均重量直径(mean weight diameter, MWD)之间的差异和相关性。通过量化分析水稳性团聚体在不同草地类型之间的差异, 评价不同草地类型恢复方式下土壤结构的稳定性, 进而选择合适的植被类型, 有助于黄土高原干旱区草地的恢复与重建。

1 材料与方法

1.1 研究区概况

研究区设在农业部兰州黄土高原生态环境重点野外科学观测试验站, 地处甘肃省兰州市七里河区彭家坪乡龚家湾村大洼山(103° 45' E, 36° 01' N), 属黄土高原半干旱丘陵沟壑区, 主要土壤类型为灰钙土。海拔为1698~1823 m, 年均气温9.3 ℃, 多年平均降水量为324.5 mm, 集中发生在7-9月, 多年平均蒸发量为1450 mm。

1.2 试验设计与方法

试验选取了天然草地和3种典型的人工草地为研究对象, 其中天然草地的优势物种为针茅(Stipa capillata)。人工草地分别为2002年开始种植的苜蓿(Medicago sativa)、冰草(Agropyron cristatum)草地, 以及柠条(Caragana korshinskii)灌木草地。各试验地邻近, 地势平坦, 土壤水分的补给只有天然降水。

于2015年6月采集土壤样品, 采样深度为0~40 cm, 每10 cm取一层土样, 每个样地3次重复。采样前去除地表的植物及枯落物。采集原状土装在硬质饭盒带回实验室, 避免碰撞挤压。将风干后的土样沿土壤的自然结构掰成小块, 大小约为1 cm, 挑出石块及根系。另外取的土样风干后, 过0.25 mm的土筛, 测定土壤有机质。

1.3 样品测定

土壤水稳性团聚体使用DIK-2001土壤团粒分析器测定。根据土壤水稳性团聚体粒径的分布计算平均重量直径(MWD)^[8]。土壤容重采用环刀法测定^[11], 土壤有机质采用重铬酸钾氧化外加热法^[12]测定。

1.4 数据分析

采用Excel 2010和SPSS 18.0软件进行数据统计与分析, Sigmaplot 12.5软件进行绘图。

2 结果与分析

2.1 土壤水稳性团聚体粒径分布

结果表明, 在0~40 cm土层, > 2 mm和< 0.25 mm两个粒级水稳性团聚体含量最多; 随土壤深度增加, > 2 mm粒径的水稳性团聚体含量逐渐减少, 而< 0.25 mm粒径的水稳性团聚体含量逐渐增加。在0~20 cm土层, 针茅草地> 2 mm粒径的水稳性团聚体含量显著高于其他三类草地(P< 0.05); 各草地类型间2.0~1.0、1.0~0.5、0.5~0.25 mm粒径的水稳性团聚体含量无显著性差异(P> 0.05)。在20~30 cm土层, 苜蓿草地> 2 mm粒径的水稳性团聚体含量显著高于冰草草地和柠条灌木草地(P< 0.05); 在20~40 cm土层, 苜蓿与针茅草地2.0~1.0、1.0~0.5、0.5~0.25 mm粒径的水稳性团聚体含量高于冰草草地与柠条灌木草地。在30~40 cm土层, 苜蓿草地> 2 mm粒径的水稳性团聚体含量显著高于其他草地类型(P< 0.05), 柠条灌木草地< 0.25 mm粒径的水稳性团聚体含量最高(图1)。

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	图1 不同草地类型0~40 cm土壤水稳性团聚体粒径分布同一粒径不同小写字母表示差异显著(P< 0.05), 下同。Fig.1 Composition of water-stable aggregate of 0-40 cm soil depth under different grassland types Different lowercase letters within the same partical size show significant difference (P< 0.05). The same below.

通过分析各草地类型间> 0.25 mm粒径的水稳性团聚体含量可知, 在0~10 cm土层, 针茅草地> 0.25 mm粒径的水稳性团聚体含量是最高的[(80.84± 13.40)%], 显著高于其他草地类型(P< 0.05), 其次是冰草草地[(62.25± 5.60)%]> 苜蓿草地[(61.46± 2.43)%]> 柠条灌木草地[(51.55± 11.34)%]。在10~20 cm土层, 针茅草地> 柠条灌木草地> 苜蓿草地> 冰草草地; 在20~30 cm和30~40 cm土层, 苜蓿草地> 0.25 mm粒径的水稳性团聚体含量显著高于其他草地(P> 0.05), 针茅草地次之, 而柠条灌木草地含量最少(图2)。

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	图2 不同草地类型0~40 cm土层> 0.25 mm粒径水稳性团聚体含量Fig.2 Water-stable aggregate content of > 0.25 mm particle size of 0-40 cm soil depth under different grassland types

2.2 土壤水稳性团聚体平均重量直径分布特征

表层0~10 cm各草地的MWD值是最大的, 随土壤深度增加, MWD值逐渐降低, 苜蓿草地MWD值下降了31%, 冰草、针茅、柠条草地分别下降了58%, 77%和65%。在0~10 cm土层, 针茅草地的MWD值比苜蓿、冰草草地及柠条灌木草地分别高40%, 27%和58%。在20~30 cm土层, 苜蓿草地的MWD值最高, 比冰草草地和柠条灌木草地高60%, 比针茅草地高45%(图3a)。MWD与> 0.25 mm土壤水稳性团聚体含量呈极显著正相关关系(R²=0.9674), MWD值越大, > 0.25 mm粒径的水稳性团聚体含量越高, 土壤大粒径的水稳性团聚体含量越多(图3b)。

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	图3 不同草地类型0~40 cm土壤平均重量直径变化(a)及与> 0.25 mm土壤水稳性团聚体含量关系(b)Fig.3 Mean weight diameter variation (a) and the relation (b) with > 0.25 mm particle size of water-stable aggregate of 0-40 cm soil depth under different grassland types

2.3 相关性分析

MWD与> 2.0 mm和2.0~1.0 mm粒径的水稳性团聚体含量呈极显著正相关关系, 与< 0.25 mm粒径的水稳性团聚体呈极显著的负相关关系(表1)。土壤容重与MWD及> 2.0 mm粒径的水稳性团聚体呈极显著负相关关系。土壤有机质与MWD及> 2.0 mm和2.0~1.0 mm粒径的水稳性团聚体含量呈极显著的正相关关系(P< 0.01)。

表1 土壤水稳性团聚体各参数之间的相关性分析 Table 1 The correlation between the parameters of water stable aggregates

3 讨论

土壤团聚体与土壤的理化性质直接相关, 其含量与粒径分布与土壤抗蚀性密切相关, 水稳性团聚体能准确地反映不同草地类型对土壤结构的影响^[8]。水稳性团聚体含量及粒径分布直接影响土壤抗侵蚀能力^[13]。随土壤深度增加, > 2 mm粒径的水稳性团聚体逐渐减少, 而< 0.25 mm粒径的水稳性团聚体含量逐渐增加。有研究表明, 表层大团聚体含量较高, 越下层大团聚体含量越少, 微团聚体含量增加^[14], 说明上层土壤的团聚体稳定性要高于下层土壤。> 0.25 mm粒径的水稳性团聚体含量越高, 说明土壤结构越稳定^[7]。在0~10 cm土层, > 0.25 mm粒径的水稳性团聚体含量表现为针茅草地> 冰草草地> 苜蓿草地> 柠条灌木草地, 说明天然草地相对于人工草地能更有效提高表层土壤团聚体稳定性; 在20~40 cm土层, 苜蓿草地的水稳性团聚体含量最高, 其次是针茅草地, 而柠条草地含量最低, 说明苜蓿草地对深层土壤结构的改良效果优于其他草地类型。针茅草地和苜蓿草地对土壤结构改善的效果相对明显。MWD值越大, 团聚体的平均粒径团聚度越高, 稳定性越强, 土壤结构性越好^[8]。在0~20 cm土层针茅草地土壤结构性最优, 而在20~40 cm土层, 苜蓿草地的土壤结构性最优。MWD与> 0.25 mm粒径的水稳性团聚体含量呈极显著的正相关关系, 说明> 0.25 mm粒径的水稳性团聚体, 尤其是较大粒径的水稳性团聚体含量越多, MWD值越大, 土壤团聚体稳定性越强, 土壤的抗侵蚀能力也越强。

土壤容重与> 2 mm粒径的水稳性团聚体含量及MWD值呈极显著的负相关关系(P< 0.01), 与< 0.25 mm粒径的水稳性团聚体含量呈极显著的正相关关系(P< 0.01)。容重越大, 土壤的抗侵蚀能力弱。而土壤水稳性大团聚体含量越高, 土壤容重越小, 进而增加土壤通透性和稳定性, 提高土壤的抗侵蚀能力。Plante等^[15]研究发现, 土壤团聚体因土壤有机质的变化而变化。土壤有机质在土壤团聚体形成中起胶结作用, 并且影响团聚体的稳定性^{[8, 16]}。本研究中, > 2 mm及2~1 mm粒径的水稳性团聚体含量及MWD值与有机质呈极显著的正相关关系(P< 0.01), 与< 0.25 mm粒径的水稳性团聚体含量呈极显著的负相关关系(P< 0.01), 说明在黄土高原地区有机质对土壤团聚体稳定性具有重要的影响, 增加土壤中有机质含量, 可以促进水稳性团聚体的形成, 提高土壤结构的稳定性, 增强土壤的抗侵蚀能力。

4 结论

MWD值越大说明大粒径团聚体数量越多, 土壤结构性越好。在土壤表层针茅草地的土壤结构性最优, 随土壤深度增加, 苜蓿草地对土壤结构的改良效果优于针茅草地, 柠条灌木草地的土壤结构性最差。苜蓿与针茅的混种对土壤团聚体的形成有更好的促进作用。容重越大, 土壤水稳性团聚体含量越低, 土壤结构性越差。增加有机质可以促进团聚体稳定性, 防止土壤侵蚀。

The authors have declared that no competing interests exist.

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[5]	Yu H Q, Li Y, Jin F H, et al. The role of increasing soil water-stable aggregates with diameter >0. 25 mm by vegetation restoration in enhancement of soil organic carbon in the Loess Plateau. Plant Nutrition and Fertilizer Science, 2012, 18(4): 877-884. 于寒青, 李勇, 金发会, 等. 黄土高原植被恢复提高大于0. 25 mm粒级水稳性团聚体在土壤增碳中的作用. 植物营养与肥料学报, 2012, 18(4): 877-884. [本文引用:2]
[6]	Zeng Q C, Li Y Y, Liu L, et al. Study on soil aggregate stability and soil erodibility in the grassland vegetation of the Loess Plateau region. Acta Agrestia Sinica, 2014, 22(4): 743-749. 曾全超, 李娅芸, 刘雷, 等. 黄土高原草地植被土壤团聚体特征与可蚀性分析. 草地学报, 2014, 22(4): 743-749. [本文引用:1]
[7]	Zhao S W, Su J, Yang Y H, et al. Influence of the soil structure in Loess Hilly region of southern Ningxia under different man-made vegetation. Research of Soil and Water Conservation, 2005, 12(3): 27-28. 赵世伟, 苏静, 杨永辉, 等. 宁南黄土丘陵区植被恢复对土壤团聚体稳定性的影响. 水土保持研究, 2005, 12(3): 27-28. [本文引用:2]
[8]	Luo Z Z, Li L L, Niu Y N, et al. Response of soil aggregate stability and soil organic carbon fractions to different growth years of alfalfa. Acta Prataculturae Sinica, 2016, 25(10): 40-47. 罗珠珠, 李玲玲, 牛伊宁, 等. 土壤团聚体稳定性及有机碳组分对苜蓿种植年限的响应. 草业学报, 2016, 25(10): 40-47. [本文引用:5]
[9]	Shao M A, Mentler A, Mayer H, et al. Soil aggregation, aggregate stability, organic carbon and nitrogen in different soil aggregate fractions under forest and shrub vegetation on the Loess Plateau, China. Catena, 2010, 81(3): 226-233. [本文引用:1]
[10]	Gao W S, Wang Y M. Review on the study of soil anti-erosibility. Bulletin of Soil and Water Conservation, 1992, 12(5): 59-63. 高维森, 王佑民. 土壤抗蚀抗冲性研究综述. 水土保持通报, 1992, 12(5): 59-63. [本文引用:1]
[11]	Wu G L, Liu Z H, Zhang L, et al. Long-term fencing improved soil properties and soil organic carbon storage in an alpine swamp meadow of western China. Plant & Soil, 2010, 332(1/2): 331-337. [本文引用:1]
[12]	Walkley A J, Black I A. An examination of the Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil Science, 1934, 37(1): 29-38. [本文引用:1]
[13]	Liu G B. Vegetation restoration and improvement process of soil anti-scourability in Loess Plateau-Ⅲ. Effect of vegetation restoration on soil humus and aggregations. Research of Soil and Water Conservation, 1997, (S1): 122-128. 刘国彬. 黄土高原草地植被恢复与土壤抗冲性形成过程──Ⅲ. 植被恢复对土壤腐殖质物质及水稳性团聚体的影响. 水土保持研究, 1997, (S1): 122-128. [本文引用:1]
[14]	Huo L, Wu T Y, Lin H M, et al. Effects of long-term fertilization on water-stable aggregates in calcic kastanozem of Loess Plateau. Chinese Journal of Applied Ecology, 2008, 19(3): 545-550. 霍琳, 武天云, 蔺海明, 等. 长期施肥对黄土高原旱地黑垆土水稳性团聚体的影响. 应用生态学报, 2008, 19(3): 545-550. [本文引用:1]
[15]	Plante A F, Mcgill W B. Soil aggregate dynamics and the retention of organic matter in laboratory-incubated soil with differing simulated tillage frequencies. Soil and Tillage Research, 2002, 66(1): 79-92. [本文引用:1]
[16]	Dong L L. Characteristics of soil water stable aggregates under different land -use types. Scientia Silvae Sinicae, 2011, 47(4): 95-100. 董莉丽. 不同土地利用类型下土壤水稳性团聚体的特征. 林业科学, 2011, 47(4): 95-100. [本文引用:1]

2008

0.0

... 黄土高原生态环境脆弱,植被退化严重,土壤侵蚀剧烈,1950年实施退耕还林还草工程以来,区域生态环境得以恢复,土壤侵蚀得到控制^[1] ...

2007

0.0

... 土壤侵蚀与土壤结构的改变有着密切联系,土壤团聚体是土壤结构的基本单位,其组成和稳定性是土壤结构变化的重要指示因子,对水土流失和入渗能力有重要影响^[2,3] ...

2002

0.0

. 2002, 13(11):1495-1498

Mechanisms of organic cementing soil aggregate formation and its theoretical models

有机胶结形成土壤团聚体的机理及理论模型

Shi Y , Chen X , Shen S M

史奕, 陈欣, 沈善敏

Soil aggregate is the basic unit of soil structure, and its formation and stabilization has direct effect on soil fertility and crop growth.For black soil with high content of organic matter,organic cementing substance is an important factor in forming soil aggregates.Based on the recent researches on organic cementing agents,this paper was focused on the nature of organic cementing substances,the effect of soil organisms and plant roots in forming soil aggregates,and the theoretical models and stable mechanisms of soil aggregate formation.

土壤团聚体是土壤结构的基本单位,其组成和稳定性直接影响土壤肥力和农作物的生长.对于有机质含量高的黑土,有机胶结物质是形成土壤团聚体的主要因素.在综合有机胶结剂和土壤团聚体的研究的基础上,阐述了有机胶结物质的特性,土壤生物和植物根系在土壤团聚体形成中的作用,土壤团聚体形成的机理及理论模型.

2001

0.0

. 2001, 15(4):122-125

Features of water-stable soil aggregate structure under different land use in Karst mountains

不同土地利用方式对岩溶山地土壤团粒结构的影响

Li Y B , Xie D T

李阳兵, 谢德体

... 各粒径水稳性团聚体的比例可以反映土壤团聚体的质量^[4],因此土壤水稳性团聚体的数量和特征可以反映土壤结构的稳定性和抗侵蚀能力^[5,6] ...

2012

0.0

. 2012, 18(4):877-884 DOI:10.11674/zwyf.2012.11478

The role of increasing soil water-stable aggregates with diameter #cod#x0003E;0.25 mm by vegetation restoration in enhancement of soil organic carbon in the Loess Plateau

黄土高原植被恢复提高大于0.25 mm粒级水稳性团聚体在土壤增碳中的作用

Yu H Q , Li Y , Jin F H

于寒青, 李勇, 金发会

1 Institute of Environment and Sustainable Development in Agriculture, CAAS, Beijing 100081, China; 2 College of Life Sciences, Henan Normal University, Xinxiang, Henan 453000, China

In this study, we investigated the changes in soil water stable aggregates of 0–5cm surface and their organic carbon contents induced by different restoration vegetation types (grass, shrub and tree) at 3 sites including Suide, Wuqi, Yichuan in Shaanxi province on the Chinese Loess Plateau. Water stable aggregates with diameters of > 2 mm and 2–0.25 mm and their organic carbon contents (SOC) were significantly increased by all vegetation types and these increases were different among three investigated sites. Compared with farmland, restoration of Pinus tabulaeformis and Caragana in Suide site resulted in an increase of SOC in water stable aggregates of >2 mm and 2–0.25 mm by 99%–153% and 219%–350%, respectively. At Wuqi site, Alfalfa and Hippophae respectively increased SOC in water stable aggregates of>2 mm and 2– 0.25 mm by 28%～30% and 85%～130%, whereas Locust tree did not increase SOC in water stable aggregates of >2 mm but increased SOC by 210% of 2– 0.25 mm diameter. At Yichuan site, Pennisetum flaccidum,Bothriochloa ischemum (L.) Keng, Sophora viciifolia and Pinus tabulaeformis respectively increased SOC in water stable aggregates of >2 mm and 2– 0.25 mm by 405%–932% and 724%–1130%. The enhancement of SOC by restoration of vegetation on cultivated slopes is mainly the increase of SOC in soil water-stable aggregates of two diameters >2 mm (514%) and 2–0.25 mm (470%), but not for other diameters. The increased values of SOC of >2 mm and 2 – 0.25 mm respectively contributed to 49% and 43% of total SOC increased by vegetation restoration while less than 16% SOC increase in other diameters of water-stable aggregates. These results suggest that the formation of water-stable aggregates of > 0.25 mm diameter through stabilization of soil structure by vegetation may play an important role in soil carbon sequestration in the eroding landscapes of the Chinese Loess Plateau.

本研究选择陕北黄土高原绥德、吴旗、宜川3个地区，调查分析了不同植被恢复类型（草、灌、乔）下0—5cm表层土壤水稳性团聚体粒径分布及其有机碳含量的变化。结果表明：不同植被恢复类型均显著提高了 >2mm和2～0.25mm 两个粒级的水稳性团聚体及其有机碳（SOC）的含量，但不同植被恢复类型的作用在3个地区有所不同。与农地相比，在绥德，油松和柠条、分别使 >2mm和2～0.25mm粒级的水稳性团聚体中的SOC含量分别提高了99%～153%和219%～350% ，但苜蓿没有明显作用；在吴旗，苜蓿、沙棘、刺槐分别使 >2mm和2～0.25mm水稳性团聚体中SOC含量分别提高了28%～30%和85%～130%，而刺槐对 >2mm水稳性团聚体没有作用，而使2～0.25mm粒级的水稳性团聚体SOC含量提高了210% ; 在宜川，白草、羊胡草、狼牙刺和油松使 >2mm和2～0.25mm粒级的水稳性团聚体中的SOC含量分别提高了405%～932%和724%～1130%。植被恢复土壤增碳主要是提高了2～0.25mm和>2mm 两个粒级的水稳性团聚体中SOC的含量，提高值分别为514%和470%，占土壤有机碳库增量的49%和43%，而对其它粒级水稳性团聚体中SOC含量的贡献小于<16%。以上研究结果说明，植被恢复稳定土层结构、促进土壤水稳性大团聚体中SOC的形成，可能在黄土丘陵侵蚀景观土壤固碳过程中起重要作用。

... 各粒径水稳性团聚体的比例可以反映土壤团聚体的质量^[4],因此土壤水稳性团聚体的数量和特征可以反映土壤结构的稳定性和抗侵蚀能力^[5,6] ...

... 植被恢复有利于促进土壤大团聚体的形成^[5] ...

2014

0.0

. 2014, 22(4):743-749

Study on soil aggregate stability and soil erodibility in the grassland vegetation of the Loess Plateau region

黄土高原草地植被土壤团聚体特征与可蚀性分析

Zeng Q C , Li Y Y , Liu L

曾全超, 李娅芸, 刘雷

... 各粒径水稳性团聚体的比例可以反映土壤团聚体的质量^[4],因此土壤水稳性团聚体的数量和特征可以反映土壤结构的稳定性和抗侵蚀能力^[5,6] ...

2005

0.0

. 2005, 12(3):27-28

Influence of the soil structure in Loess Hilly region of southern Ningxia under different man-made vegetation

宁南黄土丘陵区植被恢复对土壤团聚体稳定性的影响

Zhao S W , Su J , Yang Y H

赵世伟, 苏静, 杨永辉

... 25 mm粒径的水稳性团聚体可以作为评价土壤结构的指标,其含量越高,说明土壤结构越稳定,土壤抗侵蚀能力越强^[7,8] ...

... 25 mm粒径的水稳性团聚体含量越高,说明土壤结构越稳定^[7] ...

2016

0.0

. 2016, 25(10):40-47 DOI:doi:10.11686/cyxb2015585

Response of soil aggregate stability and soil organic carbon fractions to different growth years of alfalfa

土壤团聚体稳定性及有机碳组分对苜蓿种植年限的响应

Luo Z Z , Li L L , Niu Y N

罗珠珠, 李玲玲, 牛伊宁

This study used dry and wet sieving methods to investigate the distribution and stability of soil aggregates, their mean weight diameter (MWD) and the percentage of aggregate destruction (PAD) in land that had been planted with alfalfa ( Medicago sativa ) for a range of different growth years (3, 10, and 12 years), and compares these results with those for cropland from a long-term experiment. The relationships between soil aggregates and both stability and soil organic carbon fractions were also studied. The results showed that soil aggregates had a “V”-shaped distribution under the different treatments. With dry sieving, the aggregates primarily involved small (<0.25 mm) and large (>5 mm) particle sizes, while with wet sieving they were dominated by <0.25 mm particles. The MWD of the alfalfa soils was significantly higher than that of the cropland soils at 0-10 cm depth. The PAD of alfalfa soils was significantly lower than that of cropland and it decreased with the increasing number of alfalfa growth years. Soil organic carbon fractions diverged greatly in the different treatments. The order of TOC (total organic carbon), HFOC (heavy fraction organic carbon) and ROOC (readily oxidized organic carbon) in 0-10 cm topsoil was 12 yrs>10 yrs>cropland>3 yrs, indicating that improvement in the organic carbon of alfalfa field topsoils is associated with the number of growth years. Correlation analysis returned the highest coefficients between water-stable aggregates and LFOC (light fraction organic carbon) and ROOC, suggesting that LFOC and ROOC rather than TOC play a vital role in maintaining soil aggregate stability on the Loess Plateau.

通过设置在陇中黄土高原半干旱区的长期定位试验,应用干筛法与湿筛法比较不同种植年限苜蓿地和农田土壤团聚体粒径分布、平均重量直径(mean weight diameter,MWD)以及团聚体破坏率(percentage of aggregate destruction,PAD)的差异,分析探讨了土壤团聚体稳定性与土壤有机碳组分之间的关系。结果表明,土壤机械稳定性团聚体粒径分布呈中间低两边高的“V”型,其中>5 mm和<0.25 mm的团聚体为优势粒径;土壤水稳性团聚体以<0.25 mm的团聚体为主,平均含量达90%以上。湿筛MWD仅在0~10 cm表层土中表现为不同种植年限苜蓿显著高于农田;PAD在0~30 cm土层表现为农田显著高于不同种植年限苜蓿,且随苜蓿种植年限的延长呈降低趋势。0~50 cm剖面不同深度土壤有机碳组分在处理间存在差异,其中总有机碳(total organic carbon,TOC)、重组有机碳(heavy fraction organic carbon,HFOC)和易氧化有机碳(readily oxidized organic carbon,ROOC)在0~10 cm土层均表现为12 a>10 a>农田>3 a,说明苜蓿对土壤表层有机碳组分的提高只有达到一定种植年限之后才产生效应。相关性分析表明,与土壤TOC相比,土壤轻组有机碳(light fraction organic carbon,LFOC)和ROOC与土壤水稳性团聚体粒级分布及稳定性指标之间的相关性更为显著,说明土壤活性有机碳组分对陇中黄土高原地区土壤团聚体稳定性的贡献率比土壤总有机碳更大。

... 25 mm粒径的水稳性团聚体可以作为评价土壤结构的指标,其含量越高,说明土壤结构越稳定,土壤抗侵蚀能力越强^[7,8] ...

... 根据土壤水稳性团聚体粒径的分布计算平均重量直径(MWD)^[8] ...

... 3 讨论土壤团聚体与土壤的理化性质直接相关,其含量与粒径分布与土壤抗蚀性密切相关,水稳性团聚体能准确地反映不同草地类型对土壤结构的影响^[8] ...

... MWD值越大,团聚体的平均粒径团聚度越高,稳定性越强,土壤结构性越好^[8] ...

... 土壤有机质在土壤团聚体形成中起胶结作用,并且影响团聚体的稳定性^[8,16] ...

2010

0.0

... 不同的植物群落对团聚体稳定性影响不同^[9] ...

1992

0.0

. 1992, 12(5):59-63

Review on the study of soil anti-erosibility

土壤抗蚀抗冲性研究综述

Gao W S , Wang Y M

高维森, 王佑民

摘　要：该文是对土壤抗蚀抗冲性与其内在性质研究历史和特点的综述,并提出了今后研究的方向。更多还原

... 黄土高原受水分条件限制,植被恢复方式多以种草为主,草本植物根系能固持土壤,改良土壤结构,促进水稳性团粒的形成,降低土壤侵蚀^[10] ...

2010

0.0

... 土壤容重采用环刀法测定^[11],土壤有机质采用重铬酸钾氧化外加热法^[12]测定 ...

1934

0.0

... 土壤容重采用环刀法测定^[11],土壤有机质采用重铬酸钾氧化外加热法^[12]测定 ...

1997

0.0

... 水稳性团聚体含量及粒径分布直接影响土壤抗侵蚀能力^[13] ...

2008

0.0

. 2008, 19(3):545-550

Effects of long-term fertilization on water-stable aggregates in calcic kastanozem of Loess Plateau

长期施肥对黄土高原旱地黑垆土水稳性团聚体的影响

Huo L , Wu T Y , Lin H M

霍琳, 武天云, 蔺海明

通过27年的长期定位试验,研究了长期施肥对黄土高原旱地黑垆土水稳性团聚体的影响.结果表明:与自然土壤相比,黑垆土开垦后,0～10 cm和10～20 cm土层＞0.25 mm的水稳性团聚体含量分别下降了21.35%和38.82%;0.5 mm以上各粒级的水稳性团聚体含量均呈下降趋势,其中>5 mm和5～2 mm大粒径团聚体的下降幅度最大;而0.5～0.25 mm的水稳性团聚体含量却增加了104.75%和23.13%.0～10 cm土层各粒级水稳性团聚体含量均高于10～20 cm土层.单施有机肥和有机无机肥配施处理5～2 mm粒级的水稳性团聚体含量增加最多,>5 mm粒级次之;增施有机肥、有机无机肥配合施用和秸秆还田处理能显著增加大粒径水稳性团聚体含量,改善土壤团聚体的结构.各处理0～10 cm土壤水稳性团聚体平均质量直径(MMD)均大于10～20 cm土层;自然土壤的团聚体MMD显著高于同层次耕作土壤,长期施肥处理MMD大于无肥对照,有机物质培肥处理明显高于化肥处理.土壤团聚体MMD与＞0.25 mm水稳性团聚体含量呈显著正相关.

... 有研究表明,表层大团聚体含量较高,越下层大团聚体含量越少,微团聚体含量增加^[14],说明上层土壤的团聚体稳定性要高于下层土壤 ...

2002

0.0

... Plante等^[15]研究发现,土壤团聚体因土壤有机质的变化而变化 ...

2011

0.0

. 2011, 47(4):95-100 DOI:doi:10.11707/j.1001-7488.20110415

Characteristics of soil water stable aggregates under different land-use types

不同土地利用类型下土壤水稳性团聚体的特征

Dong L L

董莉丽

Soil aggregate stability, as a key indicator of soil structure, is a product of interactions between soil environment, management practices, and land use types. Soil samples were collected from land with different vegetation in the loess hilly-gully region. The content of the soil water stable aggregate was measured by the fast wetting and slow wetting method of Le Bissonnais. The impact of land use and wetting velocity on soil aggregate stability was analyzed. The results indicated that percentage composition of water stable aggregate with a diameter larger than 0.2 mm, mean weight diameter (MWD), geometrical mean weight (GMD) from planted forest land were larger than those of the soil from orchard and farmland. Fractal dimensions of water stable aggregate size distribution of the soil from orchard and farmland were larger than those of the soil from forests, which indicated that the soil structure under forest lands had been improved. There were significant relationships between organic matters, >0.2 mm aggregate content, MWD, GMD and D. Organic matter was the main cementing and stabilizing agent of aggregate formation. Soil aggregate stability was different with measurement methods of the fast wetting and the slow wetting. The fast wetting caused greater disruption than the slow wetting, indicating that dissipations played an important role in the collapse of soil aggregates.

土壤团聚体稳定性是土壤结构的关键性指标,是土壤环境、管理实践和土地利用类型相互作用的结果。本文应用Le Bissonnais 法中的快速和慢速湿润测定陕北黄土丘陵区不同土地利用类型土壤水稳性团聚体含量,分析土地利用类型和湿润速度对土壤团聚体水稳性的影响。结果表明:小叶杨、侧柏、油松、杏4种林地土壤＞0.2 mm水稳性团聚体质量分数、平均质量直径(MWD)和几何平均直径(GMD)较农地和苹果园土壤大,而农地和苹果园土壤团聚体粒级分布的分形维数 D 值较大,说明林地土壤结构得到明显改善。土壤有机质与＞0.2 mm,MWD,GMD和 D 值呈极显著相关,说明土壤有机质是影响土壤团聚体形成和稳定的主要胶结物质。团聚体稳定性在2种处理下存在明显差异,快速湿润对团聚体破坏大于慢速湿润,说明消散作用在土壤团聚体崩解中起主要作用。

... 土壤有机质在土壤团聚体形成中起胶结作用,并且影响团聚体的稳定性^[8,16] ...